SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2771f9c53902a13994e688d24ce439befddb2dea74315e3fd1f0917e4f85f366' 
  AND token = '0E/jyakTnjAoLqKdZb56aZHcPmKn23Q6AsjbFtU5ZjI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}